diff options
| author | dzwdz | 2021-09-18 12:23:08 +0200 |
|---|---|---|
| committer | dzwdz | 2021-09-18 12:23:08 +0200 |
| commit | a26876079cb155b013461aa525276b9cc8598ccf (patch) | |
| tree | 57ebfce84d0a390d106ae733335d8e11b7f9c8e4 | |
| parent | 27cf4b1923629cbf71609311d004914c2508c03a (diff) | |
implement NULL mounts
| -rw-r--r-- | src/init/main.c | 11 | ||||
| -rw-r--r-- | src/kernel/syscalls.c | 16 | ||||
| -rw-r--r-- | src/kernel/vfs/request.c | 3 |
3 files changed, 25 insertions, 5 deletions
diff --git a/src/init/main.c b/src/init/main.c index c81f789..233b92d 100644 --- a/src/init/main.c +++ b/src/init/main.c @@ -58,10 +58,19 @@ void fs_test(void) { } // parent: accesses the fs - log("\n"); + log("\n\n"); _syscall_mount(front, argify("/init")); read_file(argify("/init/fake.txt")); read_file(argify("/init/1.txt")); read_file(argify("/init/2.txt")); read_file(argify("/init/dir/3.txt")); + + log("\nshadowing /init/dir...\n"); + _syscall_mount(-1, argify("/init/dir")); + read_file(argify("/init/fake.txt")); + read_file(argify("/init/1.txt")); + read_file(argify("/init/2.txt")); + read_file(argify("/init/dir/3.txt")); + + log("\n"); } diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c index 1bc9694..57774c2 100644 --- a/src/kernel/syscalls.c +++ b/src/kernel/syscalls.c @@ -104,12 +104,10 @@ fail: int _syscall_mount(handle_t handle, const char __user *path, int len) { struct vfs_mount *mount = NULL; - char *path_buf; + struct vfs_backend *backend = NULL; + char *path_buf = NULL; if (len > PATH_MAX) return -1; - if (handle < 0 || handle >= HANDLE_MAX) return -1; - if (process_current->handles[handle].type != HANDLE_FS_FRONT) - return -1; // copy the path to the kernel path_buf = kmalloc(len); @@ -121,6 +119,14 @@ int _syscall_mount(handle_t handle, const char __user *path, int len) { if (len < 0) goto fail; // TODO remove trailing slash + if (handle >= 0) { // mounting a real backend + if (handle >= HANDLE_MAX) + goto fail; + if (process_current->handles[handle].type != HANDLE_FS_FRONT) + goto fail; + backend = process_current->handles[handle].fs.backend; + } // otherwise backend == NULL + // append to mount list mount = kmalloc(sizeof *mount); mount->prev = process_current->mount; @@ -128,6 +134,8 @@ int _syscall_mount(handle_t handle, const char __user *path, int len) { mount->prefix_len = len; mount->backend = process_current->handles[handle].fs.backend; process_current->mount = mount; + return 0; + fail: kfree(path_buf); kfree(mount); diff --git a/src/kernel/vfs/request.c b/src/kernel/vfs/request.c index 6159bbf..46c52b8 100644 --- a/src/kernel/vfs/request.c +++ b/src/kernel/vfs/request.c @@ -15,6 +15,9 @@ int vfs_request_create(struct vfs_request req_) { process_current->pending_req = req_; req = &process_current->pending_req; + if (!req->backend) + return vfs_request_finish(req, -1); + switch (req->backend->type) { case VFS_BACK_ROOT: ret = vfs_root_handler(req); |